We normally think of atomic clocks as the gold standard in timekeeping. The very definition of a second — in modern times, at least — is 9,192,631,770 periods of the radiation corresponding to ...

That big grandfather clock in the library might be an impressive piece of mechanical ingenuity, and an even better example of fine cabinetry, but we’d expect that the accuracy of a pendulum ...

The size, power, and other metrics of a latest-generation chip-scale atomic clock.

In 2001, Japanese physicist Hidetoshi Katori proposed a new type of atomic clock that only loses a second every 30 billion years, a period longer than the current age of the universe. The ...

Optical lattice clocks, the pinnacle of timekeeping, are key to exploring the relationship between quantum mechanics and ...